Fore-for-one twisting spindle for twisting machines or similar

ABSTRACT

The invention relates to a four-for-one twisting spindle for twisting machines of textile yarns, comprising a cylindrical basket ( 2 ), inside which a feeding bobbin ( 1 ) is supported, an upper rotating part ( 3 ) and a lower rotating part ( 4 ) which rotate in opposite directions to each other and define a first passage ( 6 ) and a second passage ( 9 ) of the yarn, respectively, along the run of the yarn, one of said upper rotating part ( 3 ) or said lower rotating part ( 4 ) being operated by external means for the transmission of the motion and transmitting the motion to the other rotating part through an epicycloidal transmission mechanism, wherein the planetary elements ( 16, 34 ) are arranged so as to form two crowns and transmit forces which are exerted between the components of said epicycloidal transmission device, along oblique force lines allowing the weight of the spindle to be transmitted from said upper rotating part ( 3 ) to said lower rotating part ( 4 ).

The present invention relates to a four-for-one twisting spindle fortwisting machines, and in particular to a device for transmitting therotation motion to the various rotating elements of said spindle.

The invention relates to the field of twisting machines and similar.Twisting operations have the purpose of twisting two or more threadstogether. The yarn obtained is called single yarn or multi-yarn,according to the number of threads used. The operation is effected bytwo machines, the doubling frame, which combines two or more threads,and the twister, which twists the threads once they have been joined.Alternatively, the threads to be twisted each derive from a differentbobbin.

As is known, the multiple twist spindles currently used in this field astwisters, envisage that the double threads which are wound onto abobbin, or the single threads wound onto two bobbins superimposed in thesame spindle, are wound from the bobbin along a run which, passingthrough devices which rotate around the bobbin, give them torsions. Theimportance of these torsions is due to the fact that the yarn obtainedhas a higher resistance and regularity, in addition to an enhancedaspect, specifically due to the torsions, with respect to its initialconditions. The twisting is then used to produce higher-quality yarns.

In particular, various twisting machines are available on the market,which differ in that they give the yarn obtained a different number oftorsions. In order to obtain a number of torsions suitable forconferring the desired characteristics to the final product, therotational rate of the rotating parts of the spindle can be increased,or the collection rate of the yarn can be reduced. Alternatively, ahigher number of torsions can be conferred to the same yarn for eachrevolution of the rotating parts, without increasing the rotation rateof the same rotating parts, thus avoiding greater wear and withoutreducing the collection rate of the yarn, thus avoiding a lowerproduction rate.

According to patent EP 1007773, in the name of Armando D'Agnolo, atwisting spindle for multiple torsions for textile threads and yarns,comprises a support for the feeding bobbin, which is kept still, twoparts rotating in opposite directions, an inner rotating part and anouter rotating part, respectively, situated under the bobbin, therotating part being coaxial with each other and with respect to the axisof the spindle, and a deflecting element situated above the bobbin. Thethread which is unwound from the bobbin first passes through thedeflecting element situated above the bobbin, it then descends towardsthe inner rotating part, defining an inner balloon around the bobbin,and passes through a passage created on said inner rotating part. Whenit reaches the exit of said passage, arranged on the rotation axis ofthe spindle, the yarn passes through a second deflecting element,integral with the outer rotating part, and subsequently a passageobtained inside said outer rotating part, it exits therefrom and rises,defining an outer balloon and is finally sent to collection means.During this run, the yarn receives two torsions for each revolution ofeach rotating part. At least one thread tensioning device is includedabove the bobbin, and the bobbin is situated inside a closed containeror basket, which extends from the support of the spindle to the upperdeflecting element. A characteristic of the spindle consists in the factthat the thread, for at least a part of its run, can form free balloons,i.e. which are not externally delimited by a container.

With reference to the driving of the rotating parts, according to patentEP 1007773, one of the two rotating parts of the spindle is driven bytraditional driving means, such as, for example, a transmission beltwhich transmits the motion from a motor to a pulley integral with therotating part, whereas the other is operated by a brushless motor.

The solution proposed in patent application EP 0611841 in the name ofTeijin Seiki Co., comprises two rotating parts which impart the desiredrotations to the yarn and a basket wherein the feeding means of thethread, or sleever to be twisted are positioned, even if the runfollowed by the yarn to be subjected to the necessary twisting isdifferent with respect to patent EP 1007773. Furthermore, with referenceto the rotating parts, in patent application EP 0611841 the transmissionbelt transmits the motion to one of the two rotating elements, but thetransfer of the motion from the rotating element directly connected tothe transmission belt to the second rotating element is effected by anepicycloidal reducer.

As is known, an epicycloidal reducer is a motion transfer systemconsisting of an inner element having a circular section, in contactwith three or more intermediate elements having a circular section,which surround it, said intermediate elements being, in turn, in contactwith the inner surface of a hollow element having a circular section,which, in turn, surrounds them. A reducer of this type is also calledplanetary reducer, as, by maintaining the outer hollow element fixed,the rotation around its axis of the inner element (also called solar)causes a rotation movement of the intermediate elements (also calledplanetary elements) around their axis and, at the same time, arevolution movement of these planetary elements around the solarelement. By interposing in suitable free spaces between contiguousplanetary elements, the prongs of a circular element, also calledplanetary-holder, said prongs sustain the thrust imparted by theplanetary elements in their movement, and begin to follow the samecircular orbit around the solar element, conferring to theplanetary-holder element a rotational movement at a reduced rate withrespect to the solar element. It is also known that the characteristicswhich make the epicycloidal reducers particularly interesting consist inthat these motion transmission mechanisms allow high reduction ratios tobe obtained, by transmitting high torques and supporting heavy loads onthe exit shaft.

The solution proposed by patent application EP 0611841 is a variation ofthe epicycloidal system described above, wherein the planetary-holder ismaintained still. Moreover, the motion is not transmitted to theplanetary elements by the inner element of the epicycloidal reducer, butby the outer element. The planetary elements, as a consequence of therotation imparted by the external element, rotate around themselves,without being able to move around the solar element, as their revolutionmovement around the solar element is prevented by the contact with theprongs of the planetary-holder, which are still.

As the planetary elements can only rotate around themselves, theytransmit the rotation movement to the solar element, which is induced torotate in the opposite direction with respect to the external element.The patent application has various embodiments of the epicycloidalreducer, but they are described very briefly, without disclosing theirproduction and assembly in detail.

The solution proposed in patent application EP 0611841 is therefore notpracticable, as, on the basis of the information given, it is notpossible to obtain a disclosure on the real actualization methods of theepicycloidal reducer entrusted with transferring the movement from therotating part activated by the transmission belt to the rotating partwhose rotation motion is transmitted through said epicycloidal reducer.

Furthermore, even if this lack of description were to be surmounted by atechnical expert in the field, who were to complete the lack ofdescription on the basis of further considerations, which are, in anycase not evident and not obvious, and the reducer were consequentlyproduced, the information obtainable from patent application EP 0611841,would lead to the production of a four-for-one twisting spindle whereinthe weight of the basket and the weight of the planetary-holder aresustained by the planetary elements. Therefore, between the planetaryholder and the planetary elements, not only is stress generated due tothe contact which prevents the revolution of the planetary elementsaround the solar element, but also additional stress due to the contactfor sustaining the weight of the planetary-holder and the basket. Thisadditional stress has several drawbacks, such as an increase in theabsorbed power, possible exceeding of the ultimate PV in the contactbetween planetary elements and planetary-holders (the PV value is theproduct of the specific load P on the projection of the contact surface,by the rate V of the contact surface; the ultimate PV is reached whenthe temperature generated by the friction increases to the maximum valueallowed for the materials in contact with each other), a higher frictionin the rolling of the planetary elements and a consequent significantreduction in the fatigue life of the elements of the epicycloidalreducer, in particular of the planetary-holder (suitably made ofmaterials having a low friction coefficient, which, however, aresubjected to higher wear).

Furthermore, the variation in stress on the reducer elements, due to theprogressive decrease in the weight of the spindle formation (or thedecrease in the weight of the bobbin during the unwinding of the yarnfrom the same) and its increase as a consequence of the insertion of anew bobbin in substitution of an exhausted bobbin, involves a variationin the stress which acts on the reducer elements which, in somesituations, could be loadless. This possibility should be avoided byusing suitably positioned pre-loading springs. This solution howeverrequires an increase in the overall stress in the contact points of thedevice and a consequent decrease in the fatigue life.

Not only this, but, according to the configuration which can be derivedtherefrom, within the limits already discussed, on the basis of thedescription of patent application EP 0611841, the planetary-holder wouldalso be subjected to stress along force lines on a plane perpendicularto the rotation axis of the spindle elements, said stress beingattributable to the oscillations of the basket caused by the rotation ofthe thread around itself.

This type of stress requires the use of a specific anti-overturningbearing. Moreover, with reference to the analogous oscillations due tothe rotation of the yarn around the bobbin from which it unwinds, thedescription of patent application EP 0611841 is not capable ofclarifying if and when the reducer can perform the anti-overturningfunction or if, also in this case, an anti-overturning bearing should beenclosed.

An objective of the present invention is therefore to provide amulti-twisting spindle for twisting machines which, thanks to aperfected transmission device for the transmission of the rotationmotion to the different rotating components of said spindle, inparticular of the epicycloidal type, in which stress interfering withthe motion transmission function is carefully avoided, is characterizedby a better distribution of the stress and a longer fatigue life.

Furthermore, an objective of the present invention is to provide atransmission device of the rotation motion to the different rotatingcomponents of a spindle, in particular of the epicycloidal type, whichis simple and easy to assemble, even out-of-line, i.e. without thenecessity of inserting the different elements of the transmissiondevice, one by one onto the spindle, but with the possibility ofassembling it separately and subsequently assembling it onto thespindle.

A further objective of the present invention is to guarantee a higherproductivity of the multi-twisting spindle, though a longer operatingfactor.

These objectives according to the present invention are achieved byproviding a four-for-one twisting spindle for twisting machines oftextile yarns, comprising a cylindrical basket, kept immobile and inwhich a feeding bobbin is supported, an upper rotating part and a lowerrotating part, situated behind the cylindrical basket, coaxial with thesame, which rotate in opposite directions to each other and define afirst passage and a second passage respectively, along the run of theyarn, said run being further defined by a deflecting element positionedabove the bobbin, a deflecting element situated along said first passageand a deflecting element situated along said second passage, said upperrotating part or said lower rotating part being operated by externalmotion transmission means and transmitting the motion to said lowerrotating part and to said upper rotating part, respectively, through anepicycloidal transmission device, whose inner element is integral withsaid lower rotating part and whose outer element is integral with saidupper rotating part, in which the planetary elements rotate aroundthemselves, being maintained in the same position by a planetary-holderelement and are arranged so as to form two crowns, a lower crown and anupper crown, respectively, the planetary elements of each of said twocrowns transmitting forces, which are exerted between the components ofsaid epicycloidal transmission device, along oblique force lines, theplanetary elements of at least one of said two crowns, transmittingforces along force lines converging downwards, in order to transmit theweight of the spindle, which rests on said upper rotating part, to saidlower rotating part.

According to the invention, the planetary elements of one of said twocrowns preferably transmit forces along force lines converging downwardsand the planetary elements of the other of said two crowns transmitforces along force lines converging upwards.

In a first alternative, according to the invention, the weight of thespindle is transmitted through the planetary elements of the lower crownand the inner element of said device of epicycloidal transmission canpreferably consist of a lower inner ring and an upper inner ring and theouter element of said device of epicycloidal transmission consists of atleast one external ring.

Moreover, said lower inner ring and said upper inner ring can beassembled with interference on a rotating shaft, which rotatesintegrally with said lower rotating part and said at least one outerring is assembled with interference on said upper rotating part; or saidupper inner ring can move freely along the direction of the rotationaxis, a load spring and a joint acting thereon, which prevents rotationwith respect to said lower inner ring; or again, the outer element ofsaid device for epicycloidal transmission consists of a lower outer ringand an upper outer ring, said lower outer ring being assembled withinterference on said upper rotating part and said upper outer ring beingfree to move along the direction of the rotating axis, a load spring anda joint acting thereon, which prevents rotation with respect to saidlower outer ring.

In a second alternative of the present invention, the weight of thespindle is transmitted through the planetary elements of the uppercrown, and in this case the inner element of said device forepicycloidal transmission preferably consists of at least one innerring, whereas the outer element of said device for epicycloidaltransmission made up of a lower outer ring and an upper outer ring.

Furthermore, said at least one inner ring can be assembled withinterference on a rotating shaft which rotates integrally with saidlower rotating part, and said lower outer ring and said upper outer ringare assembled with interference on said upper rotating part; or saidlower outer ring can move freely along the direction of the rotatingaxis, a load spring and a joint acting thereon, which prevents rotationwith respect to said upper outer ring; or again, the inner element ofsaid device for epicycloidal transmission consists of a lower inner ringand an upper inner ring, said upper inner ring being assembled withinterference on a rotating shaft, which rotates integrally with saidlower rotating part and said lower inner ring being free to move alongthe direction of the rotating axis, a load spring and a joint actingthereon, which prevents rotation with respect to said upper inner ring.

Still according to the invention, the weight of said planetary-holdercan rest directly on the planetary elements of said two crowns or doesnot rest directly on the planetary elements of neither of the twocrowns, as it is sustained by the structure of the spindle.

Still according to the invention, said planetary elements can have theshape of spheres, rolls or similar shapes, said inner and outer ringscomprising tracks which adapt themselves to the shape of said planetaryelements so as to increase the contact surface.

In these cases, said planetary-holder preferably consists of a cage witha substantially cylindrical body equipped with a series of prongssituated along the generatrices of the cylindrical body and which definehousing spaces between each other for said planetary elements; or itconsists of a cage with a substantially cylindrical body, equipped witha series of openings, situated on two different circumferences whichdefine housing spaces for said planetary elements; or it consists of acage with a substantially cylindrical body equipped with a series ofprongs placed along the generatrices of the cylindrical body and whichdefine housing spaces between each other for the planetary elementsbelonging to the upper crown and a series of openings which definehousing spaces for the planetary elements belonging to the lower crown.

Alternatively, said planetary elements have the shape of a rotationsolid with two parallel and coaxial bases at whose the centre there aretwo cylindrical pins, said planetary-holder consisting of a frame with acylindrical wall, equipped with a series of openings, situated on twodifferent circumferences, which define housings for said planetaryelements, each opening also being equipped with a pair of flaps withholes for the housing of said cylindrical pins.

The present invention will be now described, for illustrative, butnon-limiting purposes, according to a preferred embodiment, withparticular reference to the figures of the enclosed drawings, in which:

FIG. 1 shows a sectional view of a four-for-one twisting spindle fortwisting machines, according to an embodiment of the present invention;

FIG. 2 shows a sectional view of a device for the transmission of therotation movement to the different rotation components of a spindle inaccordance with the present invention, according to a first embodiment;

FIG. 3 shows a perspective view of the different elements of thetransmission device of the rotation motion of FIG. 2, with the exclusionof the spherical planetary elements;

FIG. 4 shows a sectional view of a device for the transmission of therotational motion to the different components in rotation, of a spindlein accordance with the present invention, according to a secondembodiment;

FIG. 5 shows a perspective view of the different elements of thetransmission device of the rotation motion of FIG. 4, with the exclusionof the spherical planetary elements;

FIG. 6 shows a sectional view of a device for the transmission of therotational motion to the different components in rotation, of a spindlein accordance with the present invention, according to a thirdembodiment;

FIG. 7 shows a perspective view of the different elements of thetransmission device of the rotation motion of FIG. 6, with the exclusionof the spherical planetary elements; and

FIG. 8 shows a sectional view of a transmission device of the rotationmotion to the different rotation components of a spindle in accordancewith the present invention, according to a fourth embodiment.

With reference to FIG. 1, a preferred embodiment of the multi-twistingspindle according to the present invention is schematically shown. Atwisting machine comprises one or more spindles. The spindle consists ofa feeding bobbin 1, onto which the thread is wound, situated inside acylindrical basket 2, which is kept still by the magnetic attractionbetween one or more magnets 26, integral with the cylindrical basket 2,and corresponding fixed magnets, integral with the winding machine. Anupper rotating disk 3 and a lower rotating disk 4 are situated behindthe cylindrical basket 2, which rotate in opposite directions. Thecylindrical basket 2 is assembled idle on the upper rotating disk 3. Theyarn which is to be twisted is unwound from bobbin 1 and, by means ofdeflecting means, not shown, situated above the cylindrical basket 2, isdirected downwards, defining an inner balloon, as far as the entry 5 ofa passage 6 of the upper rotating disk 3. Running through the passage 6,the yarn radially pass through the upper rotating disk 3, from theperiphery to its rotating axis, which coincides with the axis of thespindle, it then bends and continues axially as far as the lower exit 7.A deflecting pulley 8 is present in correspondence with the curve formedby the passage 6.

Through the whole passage 6 down to the lower exit 7, the yarn continuesits run through a second passage 9, along the rotation axis of a hollowshaft 10, coinciding with the spindle axis. The hollow shaft 10 ismaintained under rotation by means of a pulley 11, operated by a drivebelt, not shown, connected to a motor.

The yarn then reaches a second deflecting pulley 12 and passes through apassage 13 of the lower rotating disk 4, integral with the hollow shaft10. After defining a second outer balloon in its ascending run, the yarnreaches deflecting elements situated above the cylindrical basket 2, andfrom these is directed to collecting means.

Rotation in the opposite direction of the two rotating disks 3 and 4,allows the yarn to be subjected, during its run, to a series of twists,in particular undergoing two twists for every revolution of eachrotating part.

The solution according to the present invention consists in providingthe spindle with a particular element for the transmission of themotion, of the epicycloidal type, which allows the hollow shaft 10,driven by traditional systems, such as a drive belt, to impart arotational movement in the opposite direction with respect to the upperrotating disk 3.

With reference to FIGS. 2 and 3, in a first embodiment, the transmissiondevice of the rotational movement according to the present inventionconsists of two inner rings 14 and 15, situated one above the otheraround the hollow shaft 10 and which rotate together with said hollowshaft 10, acting as a solar element of the epicycloidal reducer, aseries of spheres 16 situated on two crowns which surround and are incontact with the surface of the lower inner ring 14 and the upper innerring 15, respectively, which act as planetary elements, and an outerring 17, whose inner surface surrounds and is in contact with both thecrown spheres 16. The outer ring 17 is integral with the upper rotatingring 3.

The spheres 16 of the two crowns are free to rotate around themselves,but their rotation around the inner ring 14 and 15 is prevented by aplanetary-holding element consisting of a cage 18, equipped with prongs19 which define housing spaces of the spheres 16.

With reference also to FIG. 1, the cage 18 is coupled with a fixed disk27, assembled on the upper rotating disk 3 by means of a ball bearing,which makes the fixed disk 27 independent of the rotation of the upperrotating disk 3, and kept immobile by means of fins having magnets 20 atthe ends, attracted by corresponding magnets 21 integral with thecylindrical basket 2. The material of the cage 18 is preferably selectedfrom those having a low friction coefficient and a good wear resistance.Whereas the spheres 16 rotate substantially without slippage on theinner rings 14 and 15 and the outer ring 17, they are in continuouscontact with slippage with the prongs 19 of the cage 18, which,specifically as a result of this contact, prevent the spheres 16 fromrotating around the inner rings 14 and 15.

More specifically, the lower inner ring 14 is assembled withinterference on the hollow shaft 10 and rotates together with it,whereas the upper inner ring 15 is free to slide with precise couplingon the hollow shaft 10. The lower inner ring 14 and the upper inner ring15 are connected to each other by means of a joint 22, which preventsthe reciprocal rotation of the two rings 14 and 15, without preventinghowever the sliding of the axis. The joint 22 may not be necessary,provided that the two inner rings 14 and 15 are equipped with flapswhich, by insertion in each other, prevent the reciprocal rotation ofthe two rings 14 and 15 even if the axial sliding is not prevented.Assembly with clearance of the upper inner ring 15 could cause frettingcorrosion phenomena due to oscillations of a small amplitude and highfrequency to which it is subjected. In order to prevent this fromoccurring, the assembly of the upper inner ring 15 on the hollow shaft10 must be effected after treatment of the surface of the hollow shaft10 or with solutions suitable for avoiding the triggering of vibrations,a first cause of the above corrosion effect. For example, o-rings can beused or Nylon® ferrules. It is also possible to avoid fretting corrosionphenomena by assembling the inner rings 14 and 15 with interference onthe hollow shaft 10.

The spheres 16 are assembled so as to transmit the motion according tooblique force lines with respect to the rotation axis of theepicycloidal reducer, thus also acting with an anti-overturningfunction, making the use of a specific anti-overturning bearingineffective, with the consequent simplification of the device. In orderto reduce the contact pressures and consequently decrease theabsorptions and lengthen their life, between the spheres 16 and theinner rings 14 and 15, and outer ring 17, the contact surfaces on therings are curved so as to correspond with the curvature of the spheres16, i.e. according to the typical terminology of the field, radiated(like a gothic arch).

The load on the transmission device, necessary for transmitting power,is imparted on the upper crown of spheres 16 through the upper innerring 15, on which a loading spring 23 acts, which in turn rests on adisk 24 fitted onto a specific seat of the hollow shaft 10. Only theload of the loading spring 23 weighs on the upper crown of spheres. Inthis way, the load can be calibrated with extreme precision and ispreferably produced with elements having a non-linear characteristic soas to control the load imparted in a pre-established form also in thepresence of ample tolerances and wear with time.

When both the inner rings 14 and 15 are assembled with interference onthe hollow shaft 10, the presence of the loading spring 23 is notnecessary, but it will be necessary to calibrate the height of the innerrings 14 and 15 so as to guarantee the necessary preloading in thecontact points between the elements of the reducer.

The cage 18 does not rest on the spheres 16, thus avoiding anyaccelerated wear phenomenon of the cage 18 itself, contrary to thespecific function of the cage 18, which is to prevent the rotation ofthe spheres 16 around the inner rings 14 and 15. The cage 18, on theother hand, is integral with the fixed disk 27 and is kept raised withrespect to the spheres 16 due to the coupling of said fixed disk 27 withthe upper rotating disk 3.

The weight of the bobbin 1 and basket 2 is concentrated, on the otherhand, on the lower crown of spheres 16, through the outer ring 17. Inthis way, the weight is discharged onto the lower inner ring 14 andconsequently onto the hollow shaft 10.

The device for the transmission of rotational movement is completed by asealing washer 25 and grease cups suitably arranged for lubricating themovement of the spheres 16, which allow the elimination of the exhaustedgrease in the case of relubrication operations.

In embodiments which envisage that the upper inner ring 15 be assembledwithout interference onto the hollow shaft 10, the device for thetransmission of rotational movement according to the present embodimentcan be opened and washed.

The assembly of the device for the transmission of rotational movementaccording to the present invention is effected by first fitting thelower inner ring 14 (together with the joint 22 when present) onto thehollow shaft 10, then the spheres 16 of the lower crown, followed by theouter ring 17, subsequently the spheres 16 of the upper crown and thenthe upper inner ring 15. Finally, when present (i.e. when the upperinner ring 15 is assembled on the hollow shaft 10 without interference),the loading spring 23 and contrast disk 24 are assembled. The cage 18 isassembled after assembling the spheres 16, which must therefore besuitably distanced during assembly. The cage 18, which must be assembledon the fixed disk 27, is preferably assembled last of all, together withsaid fixed disk 27.

With reference to FIGS. 4 and 5, these show a second embodiment of thedevice for the transmission of rotational movement to the variousrotating components of a spindle according to the present invention.

The transmission device according to this embodiment differs from theprevious embodiment in the form of the planetary-holder element, in thiscase consisting of a different cage 28, made up of a substantiallycylindrical body, tapered to about half of its height and equipped withopenings 29 which define housing spaces of the spheres 16. The openings29 are substantially cylindrical with an axis oriented towards adirection along which the forces between the inner and outer elements ofthe reducer are transmitted.

The remaining parts of the spindle and movement transmission device, inaddition to the movement transmission procedure according to thisembodiment of the transmission device are identical to those of thedevice according to the first embodiment.

The assembly of the device for the transmission of rotational movementaccording to this second embodiment is effected by first fitting thelower inner ring 14 (together with the joint 22 when present) onto thehollow shaft 10, then the cage 28, followed by the spheres 16 of thelower crown (which are inserted from the outside of the cage 28 into therespective openings 29), followed by the outer ring 17, subsequently thespheres 16 of the upper crown (which are inserted from inside the cage28 into the respective openings 29) and then the upper inner ring 15.Finally, when present (i.e. when the upper inner ring 15 is assembled onthe hollow shaft 10 without interference), the loading spring 23 andcontrast disk 24 are assembled.

As in the case of the first embodiment, the transmission device ofrotational movement according to this embodiment can be opened andwashed, at least in the embodiments wherein the upper inner ring 15 isnot assembled with interference onto the shaft 10.

With reference to FIGS. 6 and 7, these show a third embodiment of thetransmission device of rotational movement to the various rotatingcomponents of a spindle according to the present invention.

Also the transmission device of this embodiment differs from theprevious embodiments only in the form of the planetary-holder element,consisting of a cage 30, which represents a mixed solution between thoseadopted in the first two embodiments. The cage 30, in fact, has prongs31 for the housing of the spheres 16 of the upper crown and openings 32for the housing of the spheres 16 of the lower crown. This embodimenthas expedients for simplifying the assembly of the movement transmissiondevice.

In particular, the assembly of the movement transmission deviceaccording to this embodiment is effected by first fitting the lowerinner ring 14 (together with the joint 22 when present) onto the hollowshaft 10, then the cage 30, followed by the spheres 16 of the lowercrown (which are inserted from the outside of the cage 30 into therespective openings 32), followed by the outer ring 17, subsequently thespheres 16 of the upper crown (which are inserted from the upper of thecage 30 into the spaces between the prongs 31) and then the upper innerring 15. Finally, when present (i.e. when the upper inner ring 15 isassembled on the hollow shaft 10 without interference), the loadingspring 23 and contrast disk 24 are assembled. With respect to thetransmission device according to the second embodiment, the assembly ofthe spheres 16 of the upper crown is easier, as an insertion of thespheres 16 from the inside of the cage 30 is not necessary.

The transmission device of rotational movement of this embodiment canalso be opened and washed, if the upper inner ring 15 is assembledwithout interference on the hollow shaft 10.

Finally, with reference to FIG. 8, this shows a fourth embodiment of thetransmission device of rotational movement to the various rotatingcomponents of a spindle according to the present invention.

The transmission device of this embodiment differs from the previousembodiments not only in the form of the planetary-holder element 33, butalso in the form of the planetary elements 34. Said planetary elements34, in fact, are in the form of a rotational solid 35, in the case showna spherical sector, with two parallel and coaxial bases 36, equidistantfrom the centre of the spherical segment, in the centre of said bases,there being two cylindrical pins 37. The particular shape of theplanetary elements 34 is complementary to the shape of theplanetary-holder, which consists of a frame 33 with a cylindrical wall38, equipped with a series of openings, arranged on two distinctcircumferences, which define housings for said planetary elements 34,each opening also being equipped with a pair of flaps 39 with holes forthe housing of the cylindrical pins 37 of said planetary elements 34.

This particular type of coupling between the planetary-holder 33 and theplanetary elements 34, represents a solution which allows the entireassembly of the planetary-holder 33 and the planetary elements 34,together with the outer ring of the transmission device (not shown butcompletely identical to the outer ring 17 illustrated with reference tothe previous figures) facilitating the subsequent assembly of the systemof planetary-holder-planetary elements-outer ring in the spindle.

The assembly of the movement transmission device according to thisfourth embodiment is in fact effected by first fitting the lower innerring 14 (together with the joint 22 when present) onto the hollow shaft10, then the block system consisting of the planetary-holders 33,planetary elements 34 and outer ring, and subsequently the upper innerring 15. Finally, as in the previous cases, when present (i.e. when theupper inner ring 15 is assembled on the hollow shaft 10 withoutinterference), the loading spring 23 and the contrast disk 24 areassembled.

The rotational movement transmission device according to this embodimentcan also be opened and washed, if the upper inner ring 15 is assembledwithout interference on the hollow shaft 10.

The present invention is described for illustrative but non-limitingpurposes according to its preferred embodiments. It is understood,however, that variations and/or modifications can be applied by expertsin the field, all included in the relative protection scope, as definedby the enclosed claims.

1. A four-for-one twisting spindle for twisting machines of textileyarns, comprising a cylindrical basket (2), kept still and inside whicha feeding bobbin (1) is supported, an upper rotating part (3) and alower rotating part (4), situated below the cylindrical basket (2), andcoaxial thereto, which rotate in opposite directions to each other anddefine a first passage (6) and a second passage (9) of the yarn,respectively, along the run of the yarn, said run being further definedby a deflecting element situated above the bobbin (1), a deflectingelement (8) positioned along said first passage (6) and a deflectingelement (12) situated along said second passage (9), said upper rotatingpart (3) or said lower rotating part (4) being operated by externalmovement transmission means and transmitting the motion to said lowerrotating part (4) or to said upper rotating part (3), by means of anepicycloidal transmission device, whose internal element is integralwith said lower rotating part (4) and whose outer element is integralwith said upper rotating part (3), wherein the planetary elements (16,34) rotate around themselves and are maintained in the same position bymeans of a planetary-holder element (18, 28, 30, 33) and are arranged soas to form two crowns, a lower crown and an upper crown respectively,the planetary elements (16, 34) of each of said two crowns transmittingforces, which are exerted between the components of said epicycloidaltransmission device, along oblique force lines, the planetary elements(16, 34) of at least one of said two crowns transmitting forcesconverging downwards, so as to transmit the weight of the spindle, whichis concentrated on said upper rotating part (3) to said lower rotatingpart (4).
 2. The spindle according to claim 1, characterized in that theplanetary elements (16, 34) of one of said two crowns transmit forcesalong downward converging force lines and the planetary elements (16,34) of the other of said two crowns transmit forces along upwardconverging force lines.
 3. The spindle according to claim 2,characterized in that the weight of the spindle is transmitted by meansof the planetary elements (16, 34) of the lower crown.
 4. The spindleaccording to claim 3, characterized in that the inner element of saidepicycloidal transmission device consists of a lower inner ring (14) andan upper inner ring (15) and the outer element of said epicycloidaltransmission device consists of at least one outer ring (17).
 5. Thespindle according to claim 4, characterized in that said lower innerring (14) and said upper inner ring (15) are assembled with interferenceon a rotating shaft (10) which rotates integrally with said lowerrotating part (4) and said at least one outer ring (17) is assembledwith interference on said upper rotating part (3).
 6. The spindleaccording to claim 4, characterized in that said upper inner ring (15)is free to move along the direction of the rotation axis, a loadingspring (23) and a joint (22) acting thereon, which prevents rotationwith respect to said lower inner ring (14).
 7. The spindle according toclaim 4, characterized in that said outer element of said epicycloidaltransmission device consists of a lower outer ring and an upper outerring, said lower outer ring being assembled with interference on saidupper rotating part (3) and said upper outer ring being free to movealong the direction of the rotation axis, a loading spring and a jointacting thereon, which prevents rotation with respect to said lower outerring.
 8. The spindle according to claim 2, characterized in that theweight of the spindle is transmitted by means of the planetary elements(16, 34) of the upper crown.
 9. The spindle according to claim 8,characterized in that the inner element of said epicycloidaltransmission device consists of an inner ring and the outer element ofsaid epicycloidal transmission device consists of a lower outer ring andan upper outer ring.
 10. The spindle according to claim 9, characterizedin that said at least one inner ring is assembled with interference on arotating shaft (10) which rotates integrally with said lower rotatingpart (4), and said lower outer ring and said upper outer ring areassembled with interference on said upper rotating part (4).
 11. Thespindle according to claim 9, characterized in that said lower outerring is free to move along the direction of the rotation axis, a loadingspring and joint acting thereon, which prevents rotation with respect tosaid upper outer ring.
 12. The spindle according to claim 9,characterized in that the inner element of said epicycloidaltransmission device consists of a lower inner ring and an upper innerring, said upper inner ring being assembled with interference on arotating shaft (10) which rotates integrally with said lower rotatingpart (4) and said lower inner ring being free to move along thedirection of the rotation axis, a loading spring and joint actingthereon, which prevents rotation with respect to said upper inner ring.13. The spindle according to claim 1, characterized in that the weightof said planetary-holder (18, 28, 30, 33) is directly concentrated onthe planetary elements (16, 34) of one of said two crowns.
 14. Thespindle according to claim 1, characterized in that the weight of saidplanetary-holder (18, 28, 30, 33) is not directly concentrated on theplanetary elements (16, 34) of any of said two crowns, as it issustained by the structure of the spindle.
 15. The spindle according toclaim 1, characterized in that said planetary elements (16, 34) are inthe form of spheres, rolls or similar forms or derivatives, said innerrings and said outer rings comprising tracks which adapt to the form ofsaid planetary elements (16, 34) so as to increase the contact surface.16. The spindle according to claim 15, characterized in that saidplanetary-holder consists of a cage (18) with a substantiallycylindrical body equipped with a series of prongs (19) arranged alongthe generatrices of the cylindrical body and which define housing spacesbetween each other for said planetary elements (16).
 17. The spindleaccording to claim 15, characterized in that said planetary-holderelement consists of a cage (28) with a substantially cylindrical bodyequipped with a series of openings (29) arranged on two distinctcircumferences, which define housing spaces for said planetary elements(16).
 18. The spindle according to claim 15, characterized in that saidplanetary-holder consists of a cage (30) with a substantiallycylindrical body equipped with a series of prongs (31) arranged alongthe generatrices of the cylindrical body and which define housing spacesfor the planetary elements (16) belonging to the upper crown and aseries of openings (32) which define housing spaces for the planetaryelements (16) belonging to the lower crown.
 19. The spindle according toclaim 1, characterized in that said planetary elements (34) are in theform of a rotation solid (35) with two bases (36) with two parallel andcoaxial bases at whose the centre there are two cylindrical pins (37),said planetary-holder consisting of a frame (33) with a cylindrical wall(38), equipped with a series of openings, situated on two differentcircumferences, which define housings for said planetary elements (34),each opening also being equipped with a pair of flaps (39) with holesfor the housing of said cylindrical pins (37).
 20. The spindle accordingto claim 1, characterized in that the contact tracks of said elements ofsaid epicycloidal transmission device with said planetary elements (16,34) are curved so as to correspond with the curvature of the surface ofthe planetary elements (16, 34).